Hash tags (Things to know) for each lecture…


  • Use these as your study guides. Each one is a concept (not a definition).
    • I use them to write the exam
    • Create a checklist - cross them off as you study
    • Use student hours for ones you don’t quite get
    • Start with #s and expand outward when studying


#FossilClues


#EvolutionTheories


#SharedAncestry

What is evolution?

Sedimentary rocks reveal the vastness of geologic time

Fossils are glimpses into the past…

  • Geology and fossils reveal key facts:
  1. The Earth and life on Earth are old
  2. Fossils look very different across geologic time

Georges Cuvier (1769-1832): The concept of extinction

Cuvier’s finding refute the idea of species permanence

99% of all species that have existed have already gone extinct!!!

Scientists after Cuvier (i.e., Darwin) now had to account for extinction as fact



















Example: Wooly Mammoths appear and then disappear in the fossil record.

Jean-Baptiste de Lamarck: Famous for being wrong


  • Lines of descent (early evolution theory)
    • compared living giraffes with fossil forms
    • evolution = simple to more complex


  • (1) Theory of use and disuse
    • body parts used: enhanced
    • body parts disused: minimized


  • (2) Inheritance of acquired characteristics
    • changes can be passed to offspring


  • The long muscular neck of Giraffes…

According it Lamarck, Skee-Lo could get his wish

I wish I was like six-foot-nine so I can get with Leoshi…

Transitional Forms Exist in the Fossil Record



  • There appear to be connections between living things and fossils
    • Lamarck and Cuvier
    • Intermediate Creatures?


  • Whales: past and present
    • nostrils
    • pelvis
    • hind limbs!
    • unique skulls

Vestigial traits: leftover structures that have lost their function

Vestigial traits: leftover structures

Traits connections argue for Shared Ancestry

Evolution as descent with modification


The fossil record lets us explore the ancestors that anything living (including us) evolved from







  • Next Time: How did giraffes really evolve longer necks?